Saguaro Cactus Fact Sheet Plant Fact Sheet: Saguaro Cactus Identifying Features The saguaro cactus (Carnegiea gigantea) is one of the defining plants of the Sonoran Desert. These plants are large, tree-like columnar cacti that develop branches (or arms) as they age, although some never grow arms. These arms generally bend upward and can number over 25. Saguaros are covered with protective spines, white flowers in the late spring, and red fruit in summer. Habitat Saguaros are found exclusively in the Sonoran Desert. The most important factors for growth are water and temperature. If the elevation is too high, the cold weather and frost can kill the saguaro. Although the the Sonoran Desert experiences both winter and summer rains, it is thought that the Saguaro obtains most of its moisture during the summer rainy season. Range You find this cactus in southern Arizona and western Sonora, Mexico. At the northern portion of their range they are more plentiful on the warmer south facing slopes. A few stray plants can also be found in southeast California. Wild Status The saguaro is not currently listed as threatened or endangered.

Arizona has strict regulations about the harvesting, collection or destruction of this species. Life Span With the right growing conditions, it is estimated that saguaros can live to be as much as 150-200 years old. Size Saguaro are very slow growing cactus. A 10 year old plant might only be 1.5 inches tall. Saguaro can grow to be between 40-60 feet tall (12-18m). When rain is plentiful and the saguaro is fully hydrated it can weigh between 3200-4800 pounds. Quick Facts The saguaro is the largest cactus in the United States. Most of the saguaros roots are only 4-6 inches deep and radiate out as far from the plant as it is tall. There is one deep root, or tap root that extends down into the ground more than 2 feet. After the saguaro dies its woody ribs can be used to build roofs, fences, and parts of furniture. The holes that birds nested in or "saguaro boots" can be found among the dead saguaros.

Native Americans used these as water containers long before the canteen was available. Comparison Compare with the Desert Bloodwood Tree of the Australian Desert. Saguaro Cactus - Organ Pipe Cactus National Monument (U.S. National Park Service) Saguaro Cactus Saguaro Cactus can grow to heights of 45 feet NPS Photo The Saguaro Cactus (Carnegiea gigantea)The saguaro cactus (pronounced “sah-wah-roh”), is the icon of the American west. Images of these cacti are seen all through our lives as a symbol of the American Desert. A trip to the Sonoran Desert is not complete without a examining of one of these famous desert plants. These huge green columnar cactus have fascinated nearly every person who has seen one. To the local Tohono O’Odham people, the saguaro cactus are even more important. These giant cactus are not plants to the Tohono O’Odham, but a different type of humanity, and are viewed as respected members of the Tohono O’Odham Tribe.

While the saguaro cactus has become a symbol of the American West, the saguaro cactus will only grow in the Sonoran desert. As a desert indicator species, the range of the saguaro cactus is limited to southern Arizona. Saguaro cactus will grow from sea level to about 4000 feet in elevation. The farther north and higher in elevation you go, the saguaro cactus will restrict their growth to the warmer, south facing slopes. Saguaro cactus are plentiful within Organ Pipe Cactus National Monument. Impressive “saguaro forests” can be seen along the Ajo Mountain Drive . Saguaro Cactus in Bloom NPS Photo. K Linendoll The saguaro cactus is the largest cactus in the United States, and will normally reach heights of 40 feet tall. The tallest saguaro cactus ever measured towered over 78 feet into the air. The saguaro cactus grows as a column at a very slow rate, with all growth occurring at the tip, or top of the cactus. It can take 10 years for a saguaro cactus to reach 1 inch in height.

By 70 years of age, a saguaro cactus can reach 6 and a half feet tall, and will finally start to produce their first flowers. By 95-100 years in age, a saguaro cactus can reach a height of 15-16 feet, and could start to produce its first arm. By 200 years old, the saguaro cactus has reached its full height, reaching upwards of 45 feet tall. Some saguaros have been seen with dozens of arms, while other cactus never produce a single one. Why this happens remains one of the desert’s mysteries. The saguaro cactus is a master of desert survival. Every aspect of this plant is specifically designed to thrive in the sometimes harsh Sonoran Desert. The skin of the saguaro cactus covered with a thick waxy coating that waterproofs the plant, and reduces water lost to the air through transpiration. The skin of the cactus is covered with hard spines and flexible bristles as a method of defending the water stored inside.

How to Grow Saguaro Cactus: 7 Steps (with Pictures) - wikiHow How to Grow Saguaro Cactus Community Q&A The saguaro cactus is native to the state of Sonora in Mexico and small portions of California and Arizona in the United States. The saguaro is a large, tree-sized cactus that can survive up to 200 years. In its natural environment, the saguaro can reach maximum heights of 60 feet (18.3 m). The plant survives by drinking in rainwater, visibly expanding itself, and storing the water for consumption during dry periods. If you're interested in growing a saguaro, you'll most likely need to do it indoors unless you live in a native geographic area of the cactus. The saguaro can easily grow in containers and doesn't require much maintenance. However, it will take a long period of time to show true growth when cultivated inside. Follow these tips for growing and caring for a saguaro. Steps 1 Select a container for your saguaro cactus seeds. Choose a small- to medium-sized plastic planting pot with drainage holes. 2 Mix soil and fill the pot.

Saguaro, like other cacti, need extremely loose, loamy and coarse soil that is free of organic fertilizers like manure. Combine 1-part each of sand, peat moss, turf soil and garden loam. Fill the pot 3/4 full of soil. 3 Place holes in the soil for the seeds. Poke several small holes in the soil 1 inch (2.54 cm) apart using a pencil. Make the holes about 1/8 inch (0.4 cm) deep. Place the saguaro seeds in the holes and lightly pinch the soil closed over them. 4 Cover the seeds. Place plastic wrap securely over the pot. Poke holes in the plastic wrap to aerate the soil. 5 Place the pot at room temperature or warmer in a location that is well lit, but not in direct sunlight. 6 Keep the seeds moist. Sprinkle water over the soil every 10 days so the seeds don't dry out. Even when growing from seed, cacti do not like too much water, so do not water more than every 10 days. 7 Remove the plastic wrap. After 4 to 6 weeks, you will be able to remove the plastic wrap.

Keep the saguaro seedlings moist by watering once a month. Community Q&A Saguaro 1400 Independence Ave., SW, Mailstop Code: 1103 Washington DC 20250-1103 Plant of the Week Carnegiea gigantea range map. USDA PLANTS Database. Saguaro flowers open at night and close the following afternoon. They are well adapted for bat pollination. Photo by Charlie McDonald. This stately giant is well over 100 years old. Photo by Charlie McDonald. A “forest” of saguaros near the base of the Santa Catalina Mountains on the Coronado National Forest north of Tucson, Arizona. Photo by Charlie McDonald. Saguaro (Carnegiea gigantea) By Charlie McDonald Along with the howling coyote, roadrunner, and chili pepper, the saguaro (pronounced suh-WAR-oh) cactus is one of the enduring symbols of the desert Southwest. It has been immortalized in art, cinema, and advertising often juxtaposed into settings where it could never truly exist.

Actually, saguaros grow in a rather narrow slice of the Sonoran Desert in Arizona, Mexico, and a small part of California. They need rocky soils for good root anchorage, more moisture than is normal in the low deserts, and mild temperatures without any prolonged freezing. These conditions are found on bajadas that form the lower slopes of desert mountain ranges. Some of the best saguaro habitat is found on national forests. Magnificent stands of these giant cacti can be seen north and east of Phoenix in the New River, Mazatzal, and Superstition mountains on the Tonto National Forest. Equally impressive stands can be seen north of Tucson in the Santa Catalina Mountains on the Coronado National Forest. A typical saguaro is both old and huge. Plants are at least 50 years old before they flower for the first time and usually about 75 years old when the first side branches develop. Plants can live for 200 years. A giant saguaro can reach almost 50 feet in height and 10 feet in circumference. They are by far the tallest plants in their desert scrub environment. A large plant full of water can weigh up to 6 tons.

The saguaro is a keystone species that provides food and shelter for many desert animals. Saguaros have hundreds of flowers that bloom several per day from late April to early June. The flowers open at night and close the following afternoon. Lesser long-nosed bats visit the flowers at night. Birds, mostly white-winged doves, and insects, mostly honey bees, visit the flowers the following morning. The fruits mature in June and early July. The rind splits into three or four sections that peel back to expose the juicy red pulp embedded with up to 2,000 tiny seeds. The fruits ripen during the peak of drought in the early summer and are about the only moist food source for many birds, mammals, and insects during this part of the year. Saguaros make excellent nesting places for many birds. Gila woodpeckers and gilded flickers both excavate nest holes in the fleshy stems. The woodpeckers usually excavate new nest holes each year giving other birds like elf owls, house finches, ash-throated flycatchers, and purple martins an opportunity to occupy old woodpecker nests.

Red-tailed hawks and other large birds nest in the angles between the main stems and the arms. Tall saguaros make good hunting and resting perches for many birds. Saguaro Cactus - DesertUSA Saguaro Cactus Carnegiea gigantea - (Cereus giganteus) The saguaro cactus is composed of a tall, thick, fluted, columnar stem, 18 to 24 inches in diameter, often with several large branches (arms) curving upward in the most distinctive conformation of all Southwestern cacti. The skin is smooth and waxy, and the trunk and stems have stout, two inch spines clustered on their ribs. When water is absorbed, the outer pulp of the saguaro can expand like an accordion, increasing the diameter of the stem and, in this way, can increase its weight by up to a ton. The saguaro often begins life in the shelter of a "nurse" tree or shrub which can provide a shaded, moist habitat for the germination of life. The saguaro grows very slowly -- perhaps an inch a year -- but to a great height, 15 to 50 feet.

The largest plants, with more than five arms, are estimated to be 200 years old. The average old saguaro has five arms and is about 30 feet tall. The saguaro has a surprisingly shallow root system, considering its great height and weight. It is supported by a tap root that is only a pad about three feet long, as well as numerous stout roots no deeper than a foot, emanating radially from its base. More smaller roots run radially to a distance equal to the height of the saguaro. These roots wrap about rocks providing anchorage from winds across the rocky bajadas. Click on the picture to see a video of the saguaro cactus Range Sonoran Desert of extreme southeastern California, southern Arizona and adjoining northwestern Mexico. Habitat Desert slopes and flats, especially rocky bajadas. Flowers Creamy-white, three inch wide flowers with yellow centers bloom May and June. Clustered near the ends of branches, the blossoms open during cooler desert nights and close again by the next midday. The saguaro flower is the state flower of Arizona. The slow growth and great capacity of the saguaro to store water allows it to flower every year, regardless of rainfall.

The night-blooming flowers, about three inches wide, have many creamy-white petals around a tube about four inches long. Like most cactus, the buds appear on the southeastern exposure of stem tips, and flowers may completely encircle stems in a good year. A dense group of yellow stamens forms a circle at the top of the tube; the saguaro has more stamens per flower than any other desert cactus. A sweet nectar accumulates in the bottom of this tube. The saguaro can only be fertilized by cross-pollination -- pollen from a different cactus. The sweet nectar, together with the color of the flower, attracts birds, bats and insects, which in acquiring the nectar, pollinate the saguaro flower. Unlike the Queen of the Night cactus, not all of the flowers on a single saguaro bloom at the same time. Instead, over a period of a month or more, only a few of the up to 200 flowers open each night, secreting nectar into their tubes, and awaiting pollination. These flowers close about noon the following day, never to open again. If fertilization has occurred, fruit will begin to form immediately.

The three inch, oval, green fruit ripens just before the fall rainy season, splitting open to reveal the bright-red, pulpy flesh which all desert creatures seem to relish. This fruit was an especially important food source to Native Americans of the region who used the flesh, seeds and juice. Seeds from the saguaro fruit are prolific -- as many as 4,000 to a single fruit -- probably the largest number per flower of any desert cactus. While the whitewing dove (whose northern range coincides with range of the saguaro) is one of its primary pollinators, it is the Gila woodpecker and the gilded flicker who can be observed making their home in the saguaro by chiseling out small holes in the trunk. Saguaro Cactus Flower Images | Sonoran Desert Pictures Saguaro Cactus Credit: Linda & Dr. Dick Buscher The saguaro cactus (Cereus giganteus) is the indicator plant of the Sonoran Desert, found in the American Southwest and northwest Mexico. These monarchs of the desert stand as ancient sentinels over this harsh environment known for its extremes of temperature and precipitation.

Human beings lived in this region long before the saguaros began to colonize this warm, dry landscape some 10,000 years ago. Natural Bouquet Credit: Linda & Dr. Dick Buscher Each April, May and June, these columnar giants bring to the desert landscape an explosion of floral beauty that rivals any flowering season anywhere in the world. And for those American pioneer mothers who first came to this desolate land in the mid-1860s, the saguaro blossoms were always a welcoming celebratory bouquet for any desert Mother's Day celebration. Short-lived Beauty Credit: Linda & Dr. Dick Buscher saguaro cactus flower is only in bloom for less than 24 hours. Stimulated by fading sunlight, the flowers begin opening in early evening. The blossom is fully open by midnight only to be closed again by the following noon. Saguaro flowers are self-incompatible and require cross-pollination. Thus the multiple flowers produce a large quantity of pollen so that complete pollination of the blooms can occur. Flowery Appeal Credit: Linda & Dr.

Dick Buscher The average saguaro flower is about 3 inches (8 centimeters) in diameter and is found near the ends of the saguaro's stems and arms. The cream-colored petals with golden stamens and light-yellow pistils make for a spectacular display in this most challenging of desert ecosystems. The saguaro flower has more stamens than any other species of Sonoran Desert cacti flower. Unique Pollination Credit: Linda & Dr. Dick Buscher A fully mature saguaro will produce an average of 295 flowers each blooming season , which typically runs from April through June. Each flower produces about 265 milligrams of pollen and 543 mg of nectar that has a sugar content of 24 percent. The nectar has a smell similar to overripe melons. The pollen of the saguaro flower is large and heavy, so the flowers cannot be pollinated by the wind. Each flower must be fertilized by the microspores from another saguaro or another arm of the same saguaro. All fertilization occurs within the short blooming time by nectar-feeding bats, birds and insects, especially honeybees.

Pollinators in Action Credit: Linda & Dr. Dick Buscher Today, honeybees (Apis mellifera) are the most common pollinators of the saguaro flower as they are the main harvester of saguaro pollen. A typical bee collects an average of 12.2 mg of pollen on each foraging trip and can collect 23.5 pollen loads from each saguaro flower. Saguaro flowers produce nectar in two waves. The first wave reaches maximum production around 10:00 pm, just in time for the night-feeding bats. The second period of maximum nectar production occurs just before sunrise, just in time for the bees. A group of honeybees can remove all the pollen from a saguaro flower by 10:00 a.m. From Humble Beginnings Credit: Linda & Dr. Dick Buscher For such giant cacti, the saguaro begins life as a microscopic midget. This picture shows a cluster of 2-week-old saguaros. The two-pointed, fleshy green structures so prominent here are actually the dicotyledons of the saguaro.

The microscopic saguaro seedling is a whitish bump that grows from the center point where the dicotyledons join together. Teen Years Credit: Linda & Dr. Dick Buscher Saguaros grow very slowly. Under normal weather conditions, a 10-year-old saguaro may only reach a height of 8 to 10 inches (20 to 25 cm). These two, 3-foot-high (1 meter) saguaros were planted in February 1988 when they were 6 to 8-inches (15 to 20 cm) tall and as a part of a school project. All young saguaros are very sun sensitive and must grow during their first few years in the shade of another plant, known as a nurse plant. For these two young saguaros, a creosote bush and a Palo Verde tree acted as nurse plants during those early years of their growth. Signs of Adulthood Credit: Linda & Dr. Dick Buscher Sometime between 50 to 60 years of age, the first flower buds will begin to appear from the areolas of the saguaro.

The first bud will appear on the southeastern sun exposure of the stem tip, but in a good flowering year, buds will encircle the entire crown of the stem and arms. From the first appearance of a bud to the opening of the flower requires a period of 10 to 14 days depending on elevation and temperature. Longer Days Signal Changes Credit: Linda & Dr. Dick Buscher Saguaros bloom during the driest season of the Sonoran Desert. Warming temperatures along with the lengthening hours of daylight seem to be the stimulus for bud development. Saguaros growing in the southern geographic range of the Sonoran Desert will bloom first and the blooming progression will then move northward. Also, saguaros found in lower elevations will flower before those growing in higher elevations. Signs of Summer Credit: Linda & Dr. Dick Buscher The trumpet-shaped, 3 to 5-inch-long (7.6 to 13 cm) flowers are a signal of the beginning of the desert's summer season. Since the majority of the blooming time is at night, nectar-feeding bats are a major pollinator of the saguaro's flowers, especially the lesser long-nosed bat.

In fact, the flowering sequence of saguaros is timed to match the northern migration pattern of these common nocturnal desert mammals. New research has indicated that the amino acids found in the saguaro's pollen helps to stimulate and maintain lactation in the female bats. An Approaching Feast Credit: Linda & Dr. Dick Buscher The saguaro fruit begins to mature between 31 and 45 days after fertilization. The first sign of the impending feast for hungry desert animals is the appearance of a red ring around the top of the fruit. Often rain hasn't fallen in the Sonoran Desert for upward of 100 days by this point, so this explosion of edible fruit has always been a key source of food for both animals and the indigenous people of this desert. The Ripening Fare Credit: Linda & Dr. Dick Buscher The fruit continues to ripen in the ever-warming desert heat, still attached to the areoles of the saguaro. The cream-colored flower is now just a dried-up, hard, brown relic of nature's beauty that was on display only a month earlier. The hard, sharp spines (which are actually modified leaves) of the saguaro also grow from the cactus' areoles.

They not only protect this arborescent cactus from grazing animals, but also act as an ever-moving pattern of shade for the waxy stem and windbreaks from the dry, desert air. Opportunity to Survive Credit: Linda & Dr. Dick Buscher Each saguaro fruit holds up to 2,000 shiny black seeds plus sweet fleshy connective fibers. The seeds are no bigger than the head of a straight pin. If the average saguaro produces 200 fruits per year and has a reproductive life span of 100 years, it will produce over 40 million viable seeds in its lifetime. Scientists estimate that only one of those 40 million seeds will survive to become another seed-producing, mature saguaro. The Feast Presented Credit: Linda & Dr. Dick Buscher saguaro fruits. The fleshy fruit has an unmistakable odor, similar to that of a fine red wine. For the animals of the desert, the saguaro fruits provide a welcomed feast during the driest time of the Sonoran Desert year.

Birds and insects dine on the fruits while they are still attached to the saguaro and once the fruit falls to the ground, every living animal of the desert can join in the annual feast. Cherished Meals Credit: Linda & Dr. Dick Buscher Here, a male Gila-woodpecker and a curved billed thrasher have an early morning disagreement as to who will dine on this fruitful gift of the saguaro cactus. The Circle of Life Credit: Linda & Dr. Dick Buscher Modern American scientists have never documented the complete life cycle of a saguaro cactus. The first scientists arrived with the U.S. Army in the mid-1850s, and if saguaros can live for up to 200 years, their complete life cycle has yet to be seen and recorded. But death does come to these desert giants, sometimes caused by bacterial disease and other times by nature's forces. Saguaros have a very shallow taproot (only about 3 feet (1 m) deep), but a broad system of shallow lateral roots that can extend from the plants for 50 feet (15 m). High winds are often the natural cause of a saguaro's death.

Strong Support System Credit: Linda & Dr. Dick Buscher With the rotting away of the fleshy, water-storing outer tissue , the wooden ribs of the saguaro become visible. It is this ring of 12 to 30 vertical wooden ribs that extend to the entire height of the stem and length of each arm and provide the support necessary for the saguaro to grow to such great heights. The number of ribs inside the saguaro corresponds to the number of pleats on the outside skin of the saguaro. Since the majority of a living saguaro is made up of stored water, these ribs are strong enough to support an adult plant weighing upwards of 6 tons or more. Officially Chosen Credit: Linda & Dr. Dick Buscher But now it is May once again in the Sonoran Desert, and the living saguaros are exploding into full bloom. Their flower has been enjoyed and cherished by generations of humans who make their home in this desert land. The flower became the Official Flower of the Territory of Arizona in 1901 and was reaffirmed the Official Flower of the State of Arizona in 1931. Opportunity for Beauty Credit: Linda & Dr.

Dick Buscher The many patterns of blooms and buds are worthy of the grand prize in any natural art show. And with the opening and shutting of blooms each day, the saguaro provides an ever-changing living canvas. A Gift from the Desert Credit: Linda & Dr. Dick Buscher One thing is for sure, the flowers of the saguaro cactus continue to provide an amazing bouquet of natural beauty. Happy Mother's Day from the grandeur of the Sonoran Desert! previous | next Saguaro Saguaro (Carnegiea gigantea) Main Sources: Dimmitt, Mark, "Cactaceae", in Steven Phillips and Patricia Comus, eds., 2000, A Natural History of the Sonoran Desert, pp.84-93, Arizona-Sonora Desert Museum Press, Tucson; Crosswhite, Frank, 1980, "The annual saguaro harvest and crop cycle of the Papago, with reference to ecology and symbolism", Desert plants 2:1:3-62; Epple, Ann, 1995, A Field Guide to the Plants of Arizona, pp.

157-8, Lew Anne Publishing Co., Mesa AZ; Hodgson, Wendy, Food Plants of the Sonoran Desert. Our lands are remarkably rich in this largest, columnar cactus to be found in the United States. Young saguaros cannot survive either intense desert sunlight or trampling, so typically survivors begin growth under a "nurse" plant (palo verde, acacia, mesquite, creosote bush), growing about 1/2" in the first year and to 1' in about 15 years. (That its early vertical growth is slow is related to priority investment in expansion of the root system.) As the plant grows larger, its white-gray spines begin to provide protective shade for the trunk.

In 40 to 50 years, saguaros reach about 10' tall (and first begin to flower and produce fruit), and in 75 to 100 years they may sprout arm buds, at heights of 12 to 20: here is a set just beginning to form, on a plant just north of the Trail Tank, seen in September 2004: (Click on the image below to see the whole plant.) Saguaros may reach a height of 60', weigh as much as 9 tons, and reach ages of over 200 years (See below for some examples.). The great upright stem of this cactus is strengthened by an interior cylinder of wooden "ribs". The pale green, columnar trunk has pleats which enable the plant to swell and shrink like an accordion depending on rains. A mature saguaro may soak up 200 gallons during a rainstorm, only gradually transpiring its supply over long periods of drought (see images below). It can tolerate cold to below freezing, provided the duration of such temperatures is brief -- less than 24 hours.

(This explains why most saguaros in our area are found on south-facing slopes, and why around 4,000' elevation is its upper limit in our area. The northern- and higher-elevation-limits of this temperature constraint marks the limits of our Sonoran Desert, as set by the distribution of this plant.) Saguaros grow to maturity best on sloping, coarse soils, since their roots require good drainage and soil aeration. The skin of a saguaro is covered with a thick, waxy cuticle which waterproofs the surface and restricts water vapor loss to the stomates (pores provided for gas exchange). The pleats have areoles, roundish pads distributed about 1" apart and from which the spines (8-30 per areole) protrude. Spines are important not only for defense from herbivores but also for shading, thus cooling the trunk. Immediately beneath the skin is a thin layer of chlorophyll-containing cells which do most of the photosynthesis for the plant. Most of the plant's bulk is water storage tissue (which also prevents overheating -- it absorbs heat during the day and releases it at night).

The root system is shallow (aside from one tap root extending more than 2' down), but it radiates out about as far as the plant is tall, and thus eventually robs its nurse plant of moisture, eventually killing it. Growth of the above-ground plant accelerates over time, as its roots are able to absorb moisture from the briefest and lightest of rains. Botanists formerly thought that the presence of extensive stands of Saguaros only of a particular age was evidence of some kind of regional climatic, disease- or human-caused change -- for example, the presence of only old Saguaros in an area of Saguaro National Park reflected a long-term decline of the plant in that area. But more recent evidence suggests that Saguaro seeds germinate and survive in considerable numbers rather rarely, only after unusually propitious weather conditions facilitate this in particular locales. As Dimmitt (p.

188) suggests, such survival requires "several consecutive years of milder and wetter-than-average weather", conditions which occur in the various parts of the Arizona Uplands "only a few times a century." In parts of Saguaro Juniper and continguous lands, we have large numbers of rather young Saguaros, indeed on one small terrace in Lower Hot Springs Canyon one can see groupings (of six, nine, and a baker's dozen respectively) of very small plants rising up protected underneath three different nurse trees. (See below for a view of 13 young saguaros under a Palo Verde.) While this profusion may indeed reflect a gradual spreading of Saguaros into our area, it more definitely points to a recent period of propitious rainfall at this particular location.

In another location (a wash slope of Soza Mesa), we see a situation where a large saguaro has grown to dwarf its former nurse, and has also spawned a next-generation nursling: (click on the image for a closeup of the plant's base) Only when saguaro plants first germinate do they have leaves, as shown in this photo where the tiny sprouts are compared in size to a Lincoln penny: (Click on the image to enlarge it) The seedlings are extremely vulnerable at first, and only those protected by nurse plants (which provide shelter and protection from herbivores -- from mice to birds) are likely to survive. Growth rate is very slow at first, plants attaining perhaps 1 1/2 inches in height after 10 years, perhaps 2 feet tall in 30 years. Saguaros begin to flower in our area between 40 and 50 years, when they are around 8 feet tall (Dimmitt, p. 188).

Waxy-white and funnel-shaped flowers bloom in May to June, opening at night (this is a plant of the Cereus family) and remaining open part of the following day (each individual flower blooming for only one day). A mature plant may produce 200 flowers per year, a few opening each day. Bats and moths pollinate them at night, diverse insects by day. (The Cactus Bees appear to be crucial pollinators in our area.) The ovate, green fruits split open in late June and July, revealing their deep-red pulpy interiors, each fruit containing up to 2,000 tiny black seeds. A wide variety of creatures (including humans) enjoy the sweet pulp, seeds, and juice. (See Saguaro fruit & processing for an account of the ripened fruit, its harvesting and processing.) In the photos at below right, the bloom has been split to show the interior structure: at the base, the ovary (which becomes the fruit), the central pistil, and the many stamens and petals surrounding it in radial symmetry. This is the most ancient type of flower form.

(Click on the three right-hand images to enlarge.) Here (below) is a comparison of the Rabbit Ears Saguaro, located atop the hill of that name in Hot Springs Canyon, taken in 1993 and again in 2002. The growth of all four arms has been very considerable during the 9 year interval. In the June 1993 photo at left, the saguaro has almost completed its blooming, while in the May 2002 photo at right the blooms are just beginning. In June 1993 the plant was fairly full of water, while in May 2002 it shows the slendering effects of a long, almost unbroken winter drought. (The plant on the right will have a rich blossoming and harvest despite this drought, since the effects of the immediately prior rainfall become apparent in fruiting only after a year has passed. A wet spring will be directly followed by a relatively poor harvest, as happened in the spring of 2004.) Here is a photo of the largest Saguaro we have seen in our area.

(Let us know if you've seen a larger one!) It is located beside the Cascabel road just downhill from the Cascabel Community Center (the clerestory windows of which are visible behind this huge tree): We are reserving another page for reviewing the importance (both historical and contemporary) of saguaro fruit as a foodstuff -- see Saguaro fruit and processing . Below you will find further information on patterns of growth and decline. The images below -- of a multi-armed Saguaro which fell sometime during the rains of late 2001 -- illustrate the shallowness (though not the spread -- many small roots broke off under the strain of collapse) of the root system: (Click on left-below image to enlarge) Collapses of this kind are almost always caused by a combination of wind and rain (when the root-holding ground has been softened by water and wind-gusts have been unusually strong) and usually destroy multi-armed saguaros rather than single-stalk plants (because the multi-armed trees display both greater top-heaviness and larger wind-catching surfaces).

However, multiple arms in a mature saguaro also generate greater quantities of fruit production than are available to a single-stalked tree of similar height, a fact that apparently compensates for this greater structural vulnerability of size. On the other hand, many saguaros in our area die abruptly when struck by lightning, a fate which generally leaves the trunk standing. Here are two examples, on the left, near the Red Tank in August of 2003, soon after a thunderstorm, and on the right, near the High Tank, photographed in April of 2004 (long after the event -- we are not entirely sure of the cause of this collapse): (Click on the left image to enlarge it.) Saguaros are prey to a variety of ills besides bad weather. For more discussion (and images) of Saguaro ailments, decline and demise, see this link: Saguaro Ailments, Death & Decay . Since 2002, Saguaro Juniper has joined with the Earlham Southwest Field Studies division of Earlham College (Richmond, Indiana) to conduct a census of a particular saguaro population in Hot Springs Canyon.

For more details on the progress and results of this ongoing research, see the following link: Cristates bloom, just as the "normals" do. To the right, a cristate in lower Hot Springs Canyon, May 27, 2002. In the photo to the left, we see it from the south side, a great mass of saguaro flesh jutting out from the central pillar. Below, close up, the mass resolves into an elaborate array of multiple fan-shaped forms, topped by the substantial twig nest of the hawk: .(Click on the images below to enlarge them.) To the left, another view from the north in somewhat softer light, showing the massive twig nest as well as the almost "barber-pole" spiraling quality of the saguaro arms themselves. And again to the left, a closeup of the massive nest on top. The exaggerated spiraling of the main upright arms was quite striking, shown below in two images taken under different light conditions. (Note also the cristate-tipped arm below far right.) Some years after 1995, this big Saguaro died a sudden death.

We neglected our opportunities to photograph the remnants until January of 2005, when we recorded this view below: (Click on the image for a close-up.) At the same time, we photographed the crystate shown above (in January 1995), now with a much better (and still) camera: (Click on the image for a close-up.) Latin: (Carnegiea gigantea) Saguaros are the most spectacular of our native Southwestern cacti. On the top shelf in my little hobby greenhouse grows a giant. Though this giant is only 5 years old and, for now at least, 4 inches tall, it has the potential to get much larger. The plant is the saguaro cactus from the Sonoran Desert of Arizona. The saguaro cactus (Carnegiea gigantea) is a superstar amongst the cactus family both for its storied existence and size. It can reach as much as 45 feet in height though 20 to 30 feet specimens with foot thick trunks are more common.

During the first 75 years of its life, it grows as an unbranched column; thereafter it begins to branch and forms the familiar shape we know. Saguaros often live to be 150 years old. This cactus grows only in the Sonoran Desert, the driest desert in the United States that occupies 120,000 square miles of the southwestern quarter of Arizona, and adjacent areas in California, the state of Sonora in Mexico and parts of the Baja Peninsula. It occurs in areas receiving between 2 and 10 inches of rainfall per year but won’t grow in salty soils or along arroyos where floods might occur. While it tolerates frost it won’t survive where freezing conditions prevail. Saguaro stems have 20 or more ribs armed with clusters of stout thorns. The pleated arrangement of the cactus body allows it to expand when rainfall is plentiful and shrink during dry spells. In the spring the ends of the branches wear a topknot of showy white flowers. Flowering begins when plants reach about 50 years of age.

The name saguaro is a Spanish language adaptation of the name used by the Tohono O’odham tribe that inhabited the region prior to European settlement. The Latin name honors Andrew Carnegie, the steel magnate and philanthropist who provided funds for so many libraries around the nation in the early years of the 20th century. Saguaro was described in 1848 as Cereus giganteus by St. Louis botanist George Englemann, but the cacti specialists from the New York Botanical Garden - Britton and Rose - reclassified it in 1908. Carnegie, who was funding much of their research, was invited to Tucson for the big announcement but lost interest quickly when he was informed it was only a name change, not a new kind of cactus. Saguaros, for all their size and toughness, live a fragile existence. As with all plants in fragile environments, humans are their biggest threat. Because they are so slow growing and they occur in such remote areas theft is a major concern. Arizona has enacted laws preventing collection from public lands and requires an extensive paper trail to follow all wild-collected saguaros.

In an attempt to cut down on cactus rustling, RFD chips have been implanted to aid in the tracking operation. Though they live a precarious existence sometimes they strike back to extract revenge for mistreatment. Cactus plugging - a highly illegal but still common practice of pumping a cactus body full of lead by armed and drunken marauders - usually results in a dead cactus. But in February of 1982, David Grundman arrived with his shotgun for a bit of merriment but left in a hearse. Though this incident sounds like an urban legend, especially after the Austin Lounge Lizards immortalized it in their song, "Saguaro," it really happened. Apparently Grundman blasted most of the way through the trunk of a 125-year-old cactus, but it refused to fall. So, to speed things along he took a saguaro rib from a dead plant and poked at one of its giant arms. The 500-pound arm detached and fell on the hapless gunman.

Then the main trunk, made unstable by the loss of one of its arms, also toppled, falling directly on top of Grundman and as the Lizards tell us "smashed him like a bug." Saguaro seeds are produced in abundance and are readily available. Though it is easy to grow from seed, cultivation only marginally speeds its slow growth rate. The best way to enjoy these beauties is to see them in their native habitat where they can be seen in their full grandeur. By: Gerald Klingaman, retired Extension News - December 12, 2008 The University of Arkansas Division of Agriculture does not maintain lists of retail outlets where these plants can be purchased. Please check your local nursery or other retail outlets to ask about the availability of these plants for your growing area.

Question: What kind of plant is a saguaro?
Answer: CACTUS